Apparatus for feeding wires to looms for producing metallic fabrics



July 28, 1970 A. RIEKER ET AL 3,521,660

APPARATUS FOR FEEDING wxmcs TO LOOMS FOR PRODUCING METALLIC FABRICS Filed Nov. 27, 1967 Fig. 1

Inventors jdof z'elfer- 7 35 08 United States Patent Int. Cl. D0311 .17/24, 47/34 US. Cl. 139125 6 Claims ABSTRACT OF THE DISCLOSURE A wire feeding device for looms for the production of metallic fabrics, metallic screens, and metallic cloths, according to which a wire withdrawn from a supply spool is passed over and looped around two roller means having their axes arranged in substantially parallel spaced relationship to each other while said two roller means are respectively subjected to the pre-loading force of two differently strong spring means urging said two roller means away from each other, that one of said two roller means which is subjected to the pre-loading force of the stronger spring means having a brake associated therewith for exerting a braking action upon said wire supply spool when said stronger spring means overcomes the force exerted by the wire from said supply spool upon the roller means associated with said stronger means.

The present invention relates to an apparatus for feeding wires to looms for producing metallic fabrics. Metallic fabrics, especially metallic cloths, have'heretofore been woven in customary manner on looms with shuttles into which a bobbin is inserted which has the weft wire wound thereon. The transverse dimensions of such a shuttle are limited by the measurement of the alternating opening of the warp wires. This measurement is determined by the diameter and the capacity of the bobbins to be inserted. With heretofore customary looms of the type involved, every two to four minutes new bobbins have to be inserted into the shuttles, and to this end it is necessary to stop the loom and to put up wih a corresponding loss in time.

In order to overcome this drawback, it has already been suggested to produce metallic fabrics with bobbin-less, pirnless or copless shuttles in such a way that a gripper shuttle to which the end of the wire to be shot in is clamped and is beaten through the alternately opening shed whereby said gripper shuttle pulls the weft wire through which latter at the non-woven end is cut olf and turned over in a manner known per se. The weft wire is in this connection by means of a feeding device withdrawn from a stationary supply bobbin, and the end of the fed wire is respetcively connected to the gripper shuttle. The weaving by means of such a feeding device, however, has heretofore failed, particularly when producing metallic cloths or screens for the paper industry. The necessary thin soft annealed warp wire, which may have a thickness of from 0.2 to 0.3 millimeter, cannot be subjected without damage to a shock-like acceleration from a standstill to a very high speed as is required with such feeding device. An inadmissible distortion of the weft wire while exceeding its tensile limit in view of the sudden beat exerted upon the shuttle would be the result. Moreover, the

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heretofore known feeding devices are unable with very thin wires safely to prevent an entangling of the wire.

The present invention starts with such heretofore known wire feeding device as disclosed for instance in German Pat. No. 639,931 which comprises a preloaded tensioning roller for tensioning the wire which is to be withdrawn from a stationary supply roller and is to be woven by means of a bobbin-less shuttle. The said wire feeding device furthermore comprises a brake which is adapted after a predetermined tensioning movement of the tensioning roller to act upon the supply roller.

The invention is based on the finding that the above outlined drawbacks of heretofore known wire feeding devices are due primarily to the fact that with their supply roller brake which becomes effective after a certain stroke of the tensioning roller, a certain braking stroke is unavoidable and that during the said braking stroke the tensioning roller has lost its tensioning eifect. As a result thereof, a certain quantity of wire is withdrawn from the supply roller without being under tension, and it is this quantity of wire which gets entangled. Furthermore, with the heretofore known devices of the type involved it is not assured that when the wire is taken over by the shuttle and in order to avoid waste, the wire is returned under slight tension after it has been cut off.

It is an object of the present invention to provide a wire feeding device in which during the operation of the loom, the wire to be fed will in each phase of the operation remain under tension.

This object and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 is a diagrammatic side view of the feeding device according to the invention with a few elements pertaining to the loom.

FIG. 2 is a top view of a portion of the feeding device according to the invention within the range of the two tensioning rollers which in this instance are respectively formed by a group of individual rollers.

The feeding device according to the present invention is characterized primarily by an additional tensionnig roller preloaded by force storing means and exerting upon the wire a weaker tensioning effect than the tensioning roller which controls the supply bobbin brake.

In the wire feeding device according to the present invention, the wire can during a weaving operation not be overloaded or become tensionless. Overloading of the wire during the shooting-in of the shuttle by means of a picker is avoided by the fact that during the first phase of movement, first the additional tensioning roller with its smaller tensioning effect is adjusted against the storing force action. Thereupon the wire length pulled-01f during this first phase of movement is, while the supply bobbin brake is still engaged, first pulled off from the windings of the wire which surround the tensioning rollers and are decreasing windings of the wire, and is during the first phase not withdrawn from the supply bobbin which is held stationary. Only after the expiration of this phase of movement which is rather short, also that tensioning roller which is under the higher load is adjusted against the storing force acting thereupon whereby the brake is vented or disengaged. From this time on, the supply bobbin will be able to supply the remaining wire required for the entire weft length. In this way the fine metal cloth wire will be prevented from being subjected to a stress to such an ex- 3 tent that, for instance by exceeding the tensile strength limit, it will be permanently damaged.

When, after the shooting-in of the weft wire has been completed, the shuttle comes instantaneously to a standstill, first the tensioning roller under the higher preload which controls the supply bobbin brake, moves back until the brake on the supply bobbin becomes effective and brings said supply bobbin to a standstill after a certain braking stroke of the bobbin. While the supply bobbin passes through this braking stroke and during the winding-off of wire inherent thereto, the additional tensioning roller which exerts a relatively weak tensioning effect has not yet reached its end abutment. This additional tensioning roller has still sufficient stroke ahead thereof in order to be able to pull the not required wire length, which during the braking operation of the supply bobbin was wound off, into the widening wire length surrounding the tensioning rollers. After completion of this operation, this tensioning roller does not move against its abutment. Even when the wire, after being shot-in at the side of the feeding-in device, is cut off and the new wire end is at the cutting area caught by a gripping device and is by the latter transferred to a clamping device of the shuttle which is returned to the side of the wire feeding device, which means that the wire is returned by a certain distance against the feeding direction, the still effective additional tensioning roller keeps the wire in the feeding device under tension.

A further advantage of the additional tensioning roller is due to the fact that in the feeding device a particularly long wire piece is located which is already wound off and surrounds the two tensioning rollers while being under the effect of the tensioning rollers and which is available for feeding during the weaving operation by means of the nowadays customary very wide looms.

In order to provide a particularly long wire piece which is already wound off but which still remains under tension, the present invention provides that instead of the tensioning roller controlling the supply bobbin brake and, if desired, instead of the additional tensioning roller, a plurality of rollers is provided which in the manner of a block and tackle have looped therearound the wire to be tensioned.

Referring now to the drawing in detail, the feeding device shown therein comprises a base plate 11 with supports 12 and 13 for journalling a supply bobbin 14 and a deviating roller 15 respectively.

The base plate 11 has pivotally connected thereto at 18 and 19 two tilting arms 16 and 17 respectively. Tilting arm 16 is provided with a brake lining 20 for engagement with the supply bobbin 14. A spring 28 continuously urges the brake lining 20 on tilting arm 18 against the supply bobbin 14, whereas spring 29 continuously urges the tilting arm 17 against an abutment bolt 21 which latter is adjustably mounted in a holding member 22 'which is connected to the base plate 11. The ends of the tilting arms 16 and 17 respectively carry freely rotatable rollers 23 and 24. More specifically, the arm 16, as will be seen from FIG. 2, carries four rollers 23, whereas the arm 17 carries three rollers 24. The wire 26 which is withdrawn from the supply bobbin 14 first passes over the deviating roller 15 and from there passes over a roller 23. From here the wire passes to one of the rollers 24 and back to the next roller 23 and so forth until the wire end is passed from the last roller 23 to a gripper shuttle 25 engaging its end abutment. The wire is then clamped into a clamping device 25a of said shuttle 25. Such clamping device may be of any suitable standard type, e.g. of the type disclosed in German Pat. Nos. 1,057,989 and 1,147,180. The tensioning spring 28 which engages the tilting arm 16 carrying the brake lining 20 is so dimensioned that through the intervention of said arm 16 it exerts upon the wire 26 looped around the rollers a considerably higher tilting force than is exerted by the weaker tensioning spring 29 upon the tilting arm 17.

The position ofthe tilting arms 16 and 17 and of the tensioning rollers 23 and 24 is shown in FIG. 1 in solid lines for the instance that the feeding device has not been in operation. When, however, the wire 26 is pulled out so far that its end is held in the clamping device 25a of the shuttle 25, the tensioning roller 24 under the smaller preload and the arm 17 have tilted to such an extent that the arm 17 is lifted off its abutment 21 and has moved into the dot-dash line position shown in FIG. 1. The wire 26 will under these circumstances be already under tension.

When the gripper shuttle 25 in customary manner is now by means of a picker 27 beaten through the shed in the direction of the arrow A, the wire length required therefor is withdrawn first from the wire 26 which is looped in the manner of block and tackle. This looping will decrease and will tilt the arm 17 together with the roller 24 into the dash line position shown in FIG. 1. Shortly after this upward tilting movement starts, also the pull on the wire 26 becomes so strong and the loop length becomes so short that also the tilting arm 16 with the rollers 23 will be tilted upwardly against the thrust of the stronger spring 28 and will eventually move into the dash line position shown in FIG. 1. Shortly after the start of this last mentioned tilting movement, the supply bobbin 14 is freed and furnishes the required wire length. When the shuttle 25, after having traversed the shed, reaches the opposite side and at its end position engages an abutment, the arm 16 returns to its full line position and brakes the supply bobbin. The wire section which is still being pulled off during the braking stroke is in view of the return tilting of the arm 17 with the rollers 24 pertaining thereto absorbed by the again increasing looping. The arm 17 then moves to a position which is close to the dot-dash line position shown in FIG. 1. Since the wire is held fast within the fabric, it will within the described feeding device remain under tension.

It is, of course, to be understood that the present invention is, by no means, limited to the arrangement set forth above but also comprises any modifications within the scope of the appended claims. Thus, the term brake is not limited to the friction brake shown in the drawing. Furthermore, if desired, the adjusting stroke of the tensioning rollers may be effected by other means than by the provision of linked arms referred to above. It is also to be understood that instead of the tensioning springs 28 and 29 any other suitable force storing means may be employed for producing the required wire tension.

What we claim is:

1. A wire feeding device for a loom which is used in the manufacture of metallic fabricand which has a gripping shuttle and a rotatable wire supply spool mounted in a stationary location, comprising first and second tensioning roller means mounted with their axes in spaced parallel relation, said roller means being adapted to receive the wire from said supply spool which is looped therearound and to tension said wire when drawn off by said shuttle, first and second pre-loading means respectively associated with said first and second tensioning roller means continuously urging the same away from each other, one of said pre-loading means exerting upon the tensioning roller means associated therewith a preloading force less than the pre-loading force exerted by the other of said pre-loading means, and brake means applied by the other of said preloading means for exerting a braking action of variable force upon said supply spool in response to the tension in said wire against said pre-loading forces.

2. A device according to claim 1, wherein at least one of said first and second tensioning roller means comprises a plurality of rollers adapted to receive the wire loops looped around said roller means.

3. A device according to claim 1, wherein said first and second roller means are carried by arm means, each pivotally connected to a support means.

4. A device according to claim 3, wherein said first and second pre-loading means comprise springs each having References Cited one end connected to said frame means and the other end UNITED STATES PATENTS connected to a respective arm means. Klemm 5. A device according to claim 4, wherein abutment 2,245,534 6/1941 means are provided in said support means as limiting 5 3,330 304 7/1967 H ll 139-122 means for the arm means associated with the weaker 2,731,986 1/1956 Frentzel 139-126 sprrn 6. 1 A device according to claim 4, wherein said brake HENRY JAUDON Pnmary Exammer means comprises a brake lining mounted on the associated 10 Us. cl.

arm means. 139-127 

